What is polyurethane adhesive?
Polyurethane adhesive found its beginning in bookbinderies but now can be found in bookbinderies and woodworking shops alike. Developed in 1985, polyurethane adhesives were made available to the public in 1988. As an adhesive, it has many advantages over other glues. Two of the major advantages that polyurethane adhesives have over other glues are that they are waterproof and have a very low viscosity. Its low viscosity and water-resistant properties make it ideal glue for repairing books as well as for woodworking.
Polyurethane adhesives are in its fourth generation of development. It has evolved as glue from one that took days, to hours, to seconds to cure. The fourth generation polyurethane adhesive the fourth generation polyurethane adhesive made the scene in 2007 sets up and cures in a matter of seconds. You could say that as glue, it has become the quick setting epoxy of the woodworking shop and the crafts shop. The fourth generation polyurethane glues also have the lowest viscosity of all the generations that gone before.
Viscosity has many definitions but in simple terms it refers to how easily, a fluid flows under given environmental conditions, mainly temperature. The lower a fluids viscosity, the easier it flows. The viscosity of most fluids varies inversely with temperature. As the ambient temperature drops, the viscosity increases and, as the temperature increases, the viscosity of most fluids decreases. This isn’t a good property for an adhesive because they are used under a wide range of temperatures. The chemist that developed the fourth generation of polyurethane glue managed to make it viscosity stable over a very wide range of temperatures
Its water-resistant properties make it an ideal adhesive for the woodworker because it seals joints against being penetrated by water and other liquids. Accidents happen, hot and cold liquids are spilled on furniture. Overtime, liquid works it way into the cracks on glued-up coffee table tops and other such surfaces and the boards begin to separate but polyurethane adhesive with their water resistant sealant properties have made accidental spills less of a problem.
Polyurethane adhesive is a type of glue used in book binding and woodworking. Polyurethane is a class of polymers that are created from a chain of organic units, joined together with urethane links. There are a wide range of polyurethane adhesive products available. Different chemical combinations result in different properties. The chemical composition can be alerted to produce different levels of stiffness, density and hardness. The major advantage of a polyurethane adhesive is that it is water resistant. This property makes it the glue of choice for book binders and book repair firms. The glue has a very low viscosity level, cures within seconds and has a pliable state in room temperature conditions. When used in terms of adhesives, the cure time is the length of time required before the adhesive has bonded the two items together. As an adhesive, polyurethane was first developed in 1985. The first version had very specific properties. The adhesive was made available in 1988 and had
